Apparatus for comparing the color of liquids by reflected and transmitted light



April 24, 1928. 1,667,249

H. A. ELLIS APPARATUS FOR COMPARING THE COLOR OF LIQUIDS BY REFLECTED AND TRANSMITTED LIGHT Filed Feb.25, 1925 Fig.1

Patented Apr. 24, 1928.

UNITED. STATE-S PATENT 0 FF] CE.

HENRY AUGUSTUS ELLIS, or LoNDoN, ENGLAND, A sIeNoR To THE RRiTISH DRUG HOUSES, LIMITED, 0]? LONDON, EN LA D, A

CORPORATION 01* GREAT BRI AIN.

APPARATUS FOR COMPARING THE ooLoRoR LIQ IDS BY RnFLnoTnD AND TRANSMITTED LIGHT.

Application filed February 25, 1925, Serial No. 11,451, and in Great Britain November 12, 1924.

This invention relates to apparatus em.- ployed for comparing the colorof liquids by reflected and transmitted light and has for its object improvements whereby the color of liquids may. be more conveniently and reliably compared with the color of one or more standard liquids such as in the colorimetric determination of the hydrogen ion concentration.

According to the ionic hypothesis acids are regarded as salts of hydrogen and the property of acidity has been found to be due to the power of acids to increase the hydrogen ions, the concentration of which determines the degree of acidity.

The presence of an acid canbe shown by the employement of suitable indicators, such as thymol blue, methyl orange, methylared, and the hydrogen ion concentration can be ascertained by the depth and lint of color of the solution to which such indicators have been added. According to the said hypothesis bases are regarded as hydroxyl salts whose alkaline property is due to the presence of hydroxyl ions, the concentration of which may also be ascertained by the color of the solution to which an indicator has been added, which determines its alkalinity.

7 To ascertain thehydrogen or hydroxyl ion concentration comparison is made with a range of standard colors corresponding with the dili'erent degrees ot concentration.

It is found in practice'that more satisfactory results are obtained whenthe standard color is re 'nesented. by a colored fluid con tained in a transparent 'vessel'of the same shape (cylindrical, for example) and ot. the.

same dimensions as that containing the liquid undergoing examination in order that the modifications of color due to refraction and dispersion may be the same in both cases.

I havc found it convenient to use a capiL lary tube to hold the liquid to be compared but it has been found difiicult in some cases to compare the color of the liquid in so small. atube with the color of thestandard liquid contained in an equally small tube owing to the narrow band of color it a tl ords.

It is therefore 'a further object of the present invention to provide a device in WlliClly the conditions under wh ich the two fluidsare compared are identical while providing a band of substantial width of the standard. color.

concentration corresponding with each of the In some cases a series of such tubes or range 0t groups of tubes representing a solution colored with the This I opening contain I colors corresponding with different degrees of concentration, are mounted on asheet of suitablematerial transversely to the opening therein, the arrangement being such that each group has a space betweenitand the" next in which the tubeor tubes containing the specimen to be compared maybe'placed parallel to the tubes containing the standard colors, so that the lightwill pass through them at the same angle. -A numloer orjother indication of the strength is preferably "associated with each group oftubes.

I will now proceed to more particularly describe myinvention with reference to the accompanying drawings, in which Fig. 1 showsone form of the improved apparatus in front elevation;

Fig. 21is asectionIon the line 22 1; and l in Fig.

. p "F- i Fig. 3 is a view 'similar to Fig. -1,illustrating -.another lianbodiment of the inven tion.

the drawings, a sheet a of Card-bozird hasa slot (ii-opening?) and aseries of groups 0 of tubes securedto it by stitches (Z or other convenient means. A strip a of sheet material is suitably secured to the sheet (4 adjacent to the tube and may be provided with numerals at or other indications of the degree of groups a. I

In practice one or a group of tubesof cquallshape and dimensions to those constituting thegroups 0 is filled with theliquid' to beexamined and placed in one or other of the spaces 57 and the color of the light transmitted direct th rough the'opening and the said tube or vgroup oftubes as well as the color of the light transmitted through .Accmtding to theconstruction shown in the said tube or tubes after reflection from the surface fthe sheet a, is compared with the color. of the 'ligl'i'tvtransmittedi-direct and after reflection through the group of tubes 0. For this purpose the tubes should be directed towards the source of the light.

According to the construction or modification illustrated in Fig. 3 a series of single tubes c' are employed instead of the groups shown in Fig. 1.

I claim:

1. A device for comparing the color of translucent objects by reflected and transmitted light simultaneously comprising a base of suitable material having a reflecting surface; an opening formed therein; a translucent object o t' stan'da-rd colo'r secured theretoin a posit-ionto allow lightreflected from the surface of said base and trans mitted through the opening therein to pass through said tTzIllSlllCGlTi) standard and an object placed next it to becompared therewith, substantially as set forth.

2. A device for comparing the color of translucent objects by reflected and transmitted slight simultaneously corruirisi'ng a base desirable material having a reflecting si' rface; an opening formed therein; a series of translucent objects of graduated standard colors secured to said base in a position to allow light reflected: from the surface of said base. and-transmitted. through the "openinfgtherein to pass through the said series of translucent standards; and spaces between each standard o'ffthe series to enable the object that to be compared therewith tobe successively juxtaposed-to each standard, substanti'a-ll y as and tor-the purpose set forth.

A device for comparing the "color of liquids by reflected and transmitted light simultaneously comprising a plate of suit- :able sheet material having reflecting s "rt'ac'e; an lopening efoiunedi therein; a capillary tube 0t substantially uniform crosssectlfdn throughout YES length containing colored fluid secured thereto in a position r-to allow light reflected from the surface of said base and transmitted through the opening therein to pass thi oughsaid tube; and a :tubeof the same form anddimensions to contain the liquid to be compared there with, substantially asset forth.

4. A device for comparing the color "of liquids by reflected :a-nd transmitted light simultaneously con'ipiisingiia plate of suitable sheet nnrterial -=havi-nfg a reflecting surface; an opening formed therein; a group of contacting capillary tubes containing colored fluid secured thereto in a position to allow iligh't reflected from {the surface of said ,base and transmitted through theopen- :in g therein 'to pass through saidutubes; and

a similar group of :tubes of the same form and dimensions to contain the liquid to be compared therewith, substantially as set forth. v

5. A device for comparing the color of liquids by reflected and transmitted light simultaneonsly comprising atplate ofsuitable sheet material having reflecting sur-tace; an opening formed therein; a plurality of capillary tubes of substantially iun'iform cross-section throughout their length secured to said base in a. position to allow light reflected from the surface of :saidbase and transmitted through the opening therein to pass through said tubes; different stai' dard colored fluids in each of the said tubes to constitute a graduated range; a space between ea'ch tube'and a removable tube ol the same form and dimensions to contain the liquid tobe-comparedto be inscrtedin said spaces so as to be successively uxtapos'ed to each of the tubes containing the standard colored fluids, substantially as and for the purpose set forth.

'6. A device for comparing the color of liquids by reflected and t raiis'inittedlight comprising a plate of'suitabl'e sheet material having a reflecting surface; an opening formed therein; a. plurality of groups of capillary tubes secured to said base in a position to allow light reflected from the surfaceof-said base and transmitted through 7 the. opening therein to pass through said tubes; a different standard colored fluid, in each group of tubes to constitute a graduated range; a space between each group of tubes and 'a removable tube of the Same form and dimensions to contain the liqnnl to be compared to be inserted in said spaces sons-t0 be suc'cessivelyj uxtapose d to each of the groups of tubes containing 'the standard colored fluids, substantially as and 'for the purpose set forth,

,7. A device for comparing "the color of liquids, by reflected and transmitted light comprising a "plate of-suitable sheet material havi'ng a reflecting surface; an opening formed therein; a plurality of groups or capillary tubes secured to said base in a position to allow light reflected from the surface of said base and transmitted through the opening *therein to pass through' said tubesfia different standard colorefh fluid in each group of tubes to constitute a graduated range; a space 'betw'en each group of tubes; and a removable group of "tubes of the same 'form and dimensions to contain the liquid tobe compared, "to be inserted in said spaces so as tobe successively juxtaposed to each of the groups of tubes containi'ng the standard colored fluids, substantiallfiy 'as and for the purpose set forth.

In testimony whereof, I ha ve sign-ed my name to this specification at London, England, this 26'dayof January, 1925.

HENRY AUGUSTUS E'LLIS.

"Inn 

